Paul wrote:
Many thanks to Paul Lamar, Kent Russell and Matt for their suggestions on
possible improvements to my cooling system for my rotary powered SQ2000.
I just finished the majority of the
mods/improvements. Here are a few pictures. The picture labeled "Aluminum
extension added" and the picture labeled "aluminum extension" show the
new extension from two different angles. The picture
labeled "lip extending into duct" is a real embarrassment to me. The
firewall lip extended past the upper "floor" of the NACA duct, obviously
tripping and interfering with proper airflow. Can't
believe I let that one get by. (Don't have to be an engineer to
recognize that warning flag). I'll pretend it was a Monday when I did
that one.
The picture labeled "part of lip removed" and "part of lip
removed-bottom" are two views showing how I removed that nasty lip and
created a radius in it's place. The final picture labeled
"finished radius and aluminum extension" shows the final configuration. I
still need to drill 6 holes and install blind nuts to secure the
extension to the existing plenum, then a little silicone
and test flight. Hopefully, I will be able to report improved cooling
efficiency on the next flight.
Thanks again for taking the time to submit your improvement
suggestions. I really DO listen sometimes. (My wife calls it selective
listening). If anyone sees any red flags, please advise before
I secure the unit with screws and silicone tomorrow and fly it.
sincerely, Paul Conner
You will have to fasten that plate to the bottom of the rad somehow Paul.
Either that or stiffen up the back edge. The aluminum will deflect
downward
and leak air if it builds the desired pressure. Perhaps you
can seal it with RTV and pop rivet it to the rad.
I am not sure what the last two pictures show.
I just watched the Weather Channel. I see you are in a record cold snap
down
there in Alabama.
Paul Lamar
Hi, Paul....yes, I had planned on high temp RTV between the aluminum
extension plate and the radiator. Just wanted to see if anyone saw any
problems with it before applying the somewhat difficult to remove silicone
gasket material.
Regarding the last two pictures....the first is just another angle
showing the aluminum extension, and the last picture is looking directly
into the NACA duct, showing how I ground, filed and sanded a radius at the
top of the duct (bottom of firewall) as well as showing the new aluminum
plate at the bottom. (Shows both the new radius as well as the new aluminum
extension extending 2 inches into the NACA duct). Note that the 3/8 inch lip
that previously extended down into the duct has been removed and replaced
with a radiused corner.
Yep...got a cold snap down here. It was only 71 degrees today. Should
be 72 tomorrow, but back up to 80 on Thursday and Friday. Will probably fly
it Thursday or Friday to conduct a fair evaluation of the cooling, as it was
80 degrees the last time I flew it and recorded my oil and water temps. Like
to keep the test conditions as close as possible to know how much
improvement was obtained. Will apply silicone and the 6 mounting blind
nuts/screws tomorrow and it will be ready for testing. After noticing and
removing approximately 3/8 inch of firewall sticking directly into the path
of incoming air at the top of the duct, it's a wonder it cooled at all.
Thanks again for your advice and assistance. Paul Conner
I see another problem from the latest pictures but will wait for additional
test data.
Paul Lamar
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